The IEEE 802.11a, 802.11b, and 802.11g standards, which are hereby incorporated by reference, specify wireless communications systems in bands at 2.4 GHz and 5 GHz. The 802.11a standard will be referred to repeatedly herein for the purpose of example. It should be noted that the techniques described are also applicable to the 802.11g standard and to the 802.11b standard where appropriate. It would be useful if alternate systems could be developed for communication over an extended range or in noisy environments. Such communication is collectively referred to herein as extended range communication.
Channel estimation and fine frequency offset calculation are more difficult for extended range communication or communication over any other channel with low SNR. The IEEE 802.11a standard specifies a packet channel estimation preamble that includes two identical special OFDM symbols that are used for fine frequency offset calculation and channel estimation. An augmented packet preamble design and techniques for processing the augmented preamble are needed for extended range communication.